Organic gardeners know about soil replenishment beyond nitrogen,
phosphorous and potash. Plants may well grow with a shortage of
micronutrients but their food quality will be diminished. For optimal
human health, optimal soil health comes first.
Unless we adhere to the closed-loop paradigms of permaculture and
biodynamics we need to replace the various nutrients that are lost
from our garden soil by wind, sale or gift of produce, and
sequestering human waste in septic tanks.
I first became aware of the issue of soil remineralization in John
Hamaker’s 1982 book, The Survival of Civilization. Hamaker’s thesis is
that human activities are accelerating the current interglacial period
and we should remineralize soil, as glaciers do, by applying mineral
dust to our soils. By doing so we cause vigorous vegetative growth and
thereby reduce atmospheric carbon dioxide. (Yes, there is a connection
between global warming and glaciation, but that is for another day.)
In addition to obtaining and applying mineral dust we can grow plants
with deep root systems that mine minerals from depths far below
typical garden plant roots. These include alfalfa, dandelion and
trees. While most tree roots are within fifteen feet of the surface,
certain oak tree roots have been found nearly 200 feet in caves. It
follows that the leaves and rotted remains of deceased oaks may well
contain a store of essential minerals. I typically place a thick layer
of fallen oak limb pieces in the bottom of new raised beds.
Gardeners may easily verify the efficacy of mineral dust application
by preparing various soil mixes in identical-sized pots and seeding
with fast-growing plants such as radish. I did this about twenty years
ago using dust from beneath the rock crusher at Trappist Concrete
Products where I was the marketing guy. The monks dug rock and gravel
from Bryant Creek and used the screened results in concrete block
production. The dust below the crusher was considered waste.
Soil remineralization works. Who knows, remineralizing your garden
soil may revitalize you. Enjoy the journey!